Damped Vibrations

Q.

Explain how sound is produced by your school bell.

Q.

An alternating current has frequency of 50 Hz. How many times does it change its direction in one second? [2 MARKS]

Q. When the natural frequency of a body is equal to the frequency of an external periodic force is called

1. refraction
2. reflection
3. resonance

Q.

Examples of a simple harmonic motion :

1. 28.8 minutes

2. 28.8 hours

3. 1728 minutes

4. none of these

Q.

State two differences between the forced and resonant vibrations.

Q.

The diagram in Fig. 7.13 shows the displacement-time graph of a vibrating body.

(i) Name the kind of vibrations.

(ii) Give one example of such vibrations.

(iii) Why is the amplitude of vibrations gradually decreasing ?

(iv) What happens to the vibrations of the body after some time ?

Q.

A tuning fork is vibrating in air. State whether the vibrations are natural or damped ?

Q.

What are the damped vibrations? How do they differ from the free vibrations? Give one example of each.

Q. In the example of resonance in pendulum, does mass of the pendulum produce any variations in the experiment.
Suppose if the two bobs of equal length have different mass ? Does it affect its oscillations?

Q.

The displacement time graph for the vibration of a particle is given below:



The type of vibration of the particle is _______

1. Natural Vibration
   

2. Damped Vibration
   

3. Forced Vibration
   

4. Resonance

Q. If the zero of the head scale lies below the pitch scale axis, the zero error is ___.

1. absent
2. negative
3. positive
4. combined

Q.

Which of the following is true about damped vibrations?

1. The amplitude does not change with time.
   

2. There is a loss of energy in the form of heat.
   

3. The frequency of vibrations is less than the natural frequency.
   

4. There is a presence of resistive force

Q. The periodic vibrations of a body of decreasing amplitude with a resistive force are called. ​​​​

1. forced vibrations
2. resonant vibrations
3. damped vibrations
4. natural vibrations

Q.

Name the phenomenon involved in tuning a radio set to a particular station.

Q.

Define Percussion instruments.

Q.

What are damped vibrations?

Q.

The phenomenon involved, in tuning the radio set is

1. Echo

2. Timbre

3. Resonance

4. Natural Vibrations

Q. Among the given options, select the applications of simple harmonic motion.

1. 
2. 2
3. 
4. None of these

Q. The amplitude of the damped vibrations remain constant.

1. True
2. False

Q.

Draw a sketch showing the displacement against time for a body executing the damped vibrations.

Q. The periodic vibrations of a body of decreasing amplitude with a resistive force are called. ​​​​

1. forced vibrations
2. resonant vibrations
3. damped vibrations
4. natural vibrations

Q.

What happens when a metal is heated?

1. Vibration of atoms decreases.

2. Vibration of atoms remains constant.

3. Vibration of atoms breaks the metal.

4. Vibration of atoms increases.

Q.

State two differences between the forced and resonant vibrations.

Q. Which of the following does the first stanza employ?

1. Religious iconography
2. Paired alliteration
3. melancholic preaching
4. Antipathetic musing
5. Character revelation